1. Field of the Invention
The present invention relates to an electronic device including an element (e.g., an electric element such as a piezoelectric element or a semiconductor element), and a member which is bonded to the element by means of an epoxy resin adhesive.
2. Description of the Related Art
As shown in FIG. 13, a conventional electronic device includes a layered piezoelectric element (element) 100, and a driven member 200 (member other than the element 100) driven by the element 100. The driven member 200 is bonded, by means of an adhesive S, to a top surface 100a of the element 100 (see, for example, Patent Document No. 1).
As used in the present specification, claims, and drawings (hereinafter may be collectively referred to as “the present specification, etc.”), the term “piezoelectric” encompasses “piezoelectric” and “electrostrictive.” Therefore, in the present specification, etc., for example, the term “piezoelectric element” encompasses both an element having a piezoelectric effect (i.e., a piezoelectric element) and an element having an electrostrictive effect (i.e., an electrostrictive element).
The adhesive S used in such an electronic device is generally an epoxy resin adhesive. However, after application of such an epoxy resin adhesive, a portion of the “resin and additive” contained in the adhesive may ooze from the site to which the adhesive was applied. This phenomenon is called “epoxy bleed out.” Thus, as shown in FIG. 13, even when the epoxy resin adhesive S is applied only to the top surface 100a, a portion of the components of the adhesive S oozes to a side surface 100b of the element 100 due to the epoxy bleed out. In this case, when an electrode (outer surface electrode) 100c is provided on the side surface 100b of the element 100, a part of the bled-out components of the adhesive S covers the electrode 100c. Therefore, when the electrode 100c is “an electrode for connecting the element 100 to an external circuit,” a problem may arise in that the area of a solderable region of the electrode 100c is reduced, resulting in reduction of soldering strength, or insufficient connection to the external circuit. Further, another problem may arise in that the electrode 100c provided on the side surface 100b is impaired through reaction with a part of the bled-out components of the adhesive S.